in this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. the inner and outer cylinders are kept at constanttemperature ti and to respectively, where ti>to. the annular space is filled with alumina-water nanofluid.the governing equations with the corresponded boundary conditions in the polar coord...

In this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. The inner and outer cylinders are kept at constanttemperature Ti and To respectively, where Ti>To. The annular space is filled with Alumina-water nanofluid.The governing equations with the corresponded boundary conditions in the polar coord...

The attention of the present paper is focused on the intensive heat removal with arrays of impinging jets. Three jet configurations are tested which involve variation of geometric parameters such as nozzle shape, diameter and nozzle-tonozzle spacing and impingement distance and of flow rate. The convective heat transfer coefficient is measured with infrared thermography applied to the heatedthi...

A numerical simulation on confined impinging circular jet working with a mixture of water and Al2O3 nanoparticles is investigated. The flow is turbulent and a constant heat flux is applied on the heated plate. A two-phase mixture model approach has been adopted. Different nozzle-to-plate distance, nanoparticle volume concentrations and Reynolds number have been considered to study the thermal p...

In this study, CFD calculations were made in order to analyse the thermal behaviour of yoghurt in a plate heat exchanger, the yoghurt viscosity being described by a Herschel–Bulkley model. The influence of Reynolds number on local Nusselt numbers was analysed as well as the influence of entry effects on average Nusselt number. Numerical runs considering and discarding the influence of temperatu...

This article reports a numerical study of double-diffusive convection in a fluidsaturated vertical porous annulus subjected to discrete heat and mass fluxes from a portion of the inner wall. The outer wall is maintained at uniform temperature and concentration, while the top and bottomwalls are adiabatic and impermeable to mass transfer. The physical model for the momentum equation is formulate...

In this paper, the bioconvective flow in a porous square cavity containing oxytactic microorganism in the presence of chemical reaction is investigated. The bioconvection flow and heat transfer in porous media are formulated based on the Darcy model of Boussinesq approximation. The governing partial differential equations are solved using the Galerkin finite element method. The computational nu...

Experimental study of natural convection heat transfer inside smooth and rough surfaces of vertical and inclined equilateral triangular channels of different inclination angles with a uniformly heated surface are performed. The inclination angle is changed from 15o to 90o. Smooth and rough surface of average roughness (0.02mm) are used and their effect on the heat transfer characteristics are s...

Abstract—In this numerical study, effects of using Al2O3-water nanofluid on the rate of heat transfer have been investigated. Physical model is a square enclosure with insulated top and bottom horizontal walls, while the vertical walls are kept at different constant temperatures. Two appropriate models are used to evaluate the viscosity and thermal conductivity of nanofluid. The governing strea...